Spur-hobbing machine



w. F. z'x'M'MERMANN SPUR HOBBING MACHINE Filed Aug. 27. 1924 5Sheets-Sheet 1 `A ril 19 1927.

p w. F. ZIMMERMANN SPUR HOBBING MACHINE Filed Aufl. 27. 1924 5Sheets-Sheet 2 l 625,580 'April 19 1927 w. F. ZIMMERMANN SPUR HOBBINGMACHINE Filed Auen. 27. 1924 5 Sheets-Sheet 3 April 19 1927' w. F.ZIMMERMANN SPUR HOBBING MACHINE 5 Sheets-Sheet 4.

Filed Aux. 27. 1924 A ril 19 1927. 1625580 p w.-F. ZIMMERMANN SPURHOBBING MACHINE Filed Aug. 27. 1924 5 Sheets-Sheet 5 lllllllllllll Ijwventoz MM M' 1 llmbauu Patented Apr. 19, 1927.

UNITED STATES PATENT OFFICE.

WILLIAM F. ZIMMERMANN, F MAPLEWOOD, NEW JERSEY, ASSIGNOR TO GOULD &

n 'EBEE/HARDE OF NEWARK, NEWJERSEY, A CORPORATION OF NEW JERSEY.

SPUR-Homme MAGHINE.

Application led August'27, 1924. rSerial No. 734,487.

. This invention deals with bobbing-machines and it undertakes so toimprove upon the mechanism of my prior U. S. Patent No. 1,472,767, thatthe principles of constructon thereof may be carried forwardv andutilized in an even more simple, rigid and sturdy Y manner, and at thesame time render available aV machine exhibiting various conveniences inpoint of an invariable location of the work, in respect to themanipulatability of the control levers, in regard tosafety interlockelements, etc. n

In conjunction with the foregoing obJectives, this inventioncontemplates means for enabling the cutter andthe work to be quicklybrought nearly into vthe tooling relation,

and for enabling the tooling operation thereupon to be brought intoaction at the slower rate appropriate to the capacity of the cutter;the. system embracing certain interlocking controls in the nature ofsafety characteristics to guard the user against causing dama'ge througherrors in judgment, improper manipulations or neglect, and also toenable the user quickly to terminate the tooling operation and quicklyto withdraw the cutter from the work in case the action requirescorrection. Thus, when the cutter is normally feeding into the work, orwhen it is partly in the blank and the feed has been discontinued, it isnot possible for the user (by the mere manipulation of any single lever)to impart a downward rapid traverse to the cutter-in these circumstancesand thereby cause damage. On the other hand, the cutter may `at alltimes be withdrawn quickly from thev workvfor purposes of inspection orcorrection. Again, to guard against simultaneously feeding both thecutter and the stanchion, there is provided an interlock between therespective levers that control those functions.

tures will bepointed out hereinafter.A

To afford greater facility in the manipula- 15v tion of the machine,this invent-ion contemplates various conveniences in the operativeelements thereof.` For example, it is not necessary that the cuttershall be rotating in order to utilize the means for accomplishing apower traverse since the latter may be resorted to either while thecutter spindle is idle or in operation. This.' and other characteristicsof convenience will be Other safety feadriven.

explained in detail in connection with the drawings which typify oneembodiment of the features characteristic of lthis invention, and insuch drawings:

Fig. 1 is a side elevationof a hobbingmachine showing a. fixed workspindle and a shiftable stanchion supporting a head slidable thereonwhich carries the hob spindle. Fig. 2 is a'plan. and Figs. 3 and 4 arerear and front end elevations of the machine;

Fig. 5 is a skeleton of the transmission syste-m and control levers forperforming the various movements of the working and positioning elementsofthe machine. Fig. 6 is a sectional detail of a friction coupllngbetween the prime-mover and a part of the transmission system. Fig. 7 isa side elevation' in detail of a portion ofthe interlockmg controlsystem for the quick traverse and feed for the hob-carrying head. Fig. 81s a condensedfragmentary side-elevation of the means actuated by thecutter-slide for automatically operating the manually-operable leversfor controlling the feed and the quick-traverse. Fig. 11 is anend-elevation of said levers. Fig. 9 is a detailof the spring snapclutch for throwing in and out the feed transmission. Fig. 1t) is adetail of the spring-detent for urging the feed hand-lever into eitherone or the other of its alternative positions; i

The bed A, in this embodiment, is elongated and positioned horizontallyand provides a forward working region in which the work spindle isdirectly journaled so as lto occupy 'a fixed position, and the bedprovides also a rear `mechanism supportingil region on which thestanchion is slidably mounted. The'work ,spindle W is shown journaledVin a lixed'be'aring A and it extends downwardly into the interior of thebed as indicatedby W and, at its lower end, carries a worm-wheel W2 bywhich it is The portion of the bed that houses the wormwhee1 W? lis,appropriately enlarged to contain' that wheel and, inasmuch as the wheel.occupies a fixed position in space, the bed admits of being ribbed andreinforced closely to the wheel and thus made very rigid as will beunderstood without illustration.l It is noteworthy that by thus givingthe work spindle a fixed position at the forward end of the bed, it isat all times quickly accessible to the user and it isA not at one timefurther from the end of the bed than at another as often happens whenthe work spindle is shiftable 1n position. The mounting of the spindleis accomplished in a very solid manner with the object of realizing theei'ect of an anvil so that itvirtually supports the work substantiallyas solidly as though it was clamped to the bed itself and, inconsequence, the tendency to vibrate and chatter is reduced to aVminimum.

The stanchion S is in the nature of a heavy box-like casting which isprovided with slideways S and SB at right angles to one another; theslideways S restingon the slideways S3 provided by the surface"of thebed and arranged to permit the heavy stanchien to be slid towards andaway from the liti the tooling operation.

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axis of the Work spindle for the purpose et determining the diameter ofthe gear. G to be cut by the machine.` The purpose of the transverseslideways SL is to support and guide a head H which is thus Shiftableparallel With the axis of the Work-spindle so that the cutter or hub(which is carried by the head) may in the course ofthe feeding movementcut the teeth of the gear G. It will be understood that this head H issuitably gibbed to the slideways S2 and, .in order to counterbalance theWeightl of the head H, a counteriveight H* may be arranged to rise anddescend in an appropriate Well provided by the stanchion S; conventionalropes and pulleysld2 and HS being provided as will be understood.

it is to be noted that the stanchion, being heavy and massive, is ineffect a part of the solid bed itself because when clamped down to thatbed, it becomes very solid therewith owing to the action of the clampsaugmented by the Weight of the stanchion and by reason of the fact thatthe base of the stanehion S is very extensive so as to resisteffectively such overturning forces as result from the pressure et thehob against the Worlr during lt will likewise be noted that thestanchion requires tobe shifted only when a change is to be made in thediameter of the gears being cut which ordinarily would be quiteinfrequent and it will also be noted that the shifting of the stanchiondoes not reduce the facility of access Vof the user 'to the Worlrspindle and does not interpose obstructions When brought closer to thatspindle. It will also be noted that the slide# ways S at the base of thestanchion runs to a region substantially underlying the head H so thatthis construction avoids the objectionable overhang which isnecessitated whenever the Work spindle is mounted on a carriage whichslides on the bed.

The transmission system forV rotating both the Work s indle and the heb,and for progressively ceding the head H, and for shift ing the positionof the stanchion S, and for genauso varying the rates of rotations andfor shifting the parts quickly or slowly as the case may be, will now bedescribed.

rlhis transmission is in the nature of a balanced drive and comprehelidsan intermediate splined shaft X and two main trans mission shafts Y andZgshaft Y being also two spur gears P2 and P and the two angle gears I"and P5. The splined transmission haft Y is journaled in the shiftablestanchion so as bodily totravel therewith and Vat its lower end isprovided with an angle gear y which meshes with an angle gear a," whichis splined to the intermediate shaft K. The cutter C is mounted on aspindle o which is journaled in the head H at a ixed angle slopingeither to the right or to the lett as shown by Fig. 4:. This angle maybe in the neighborhood of live degrees for a single thread hob or tendegrees for a double thread heb. This angle being lixed and not of greatmagnitude admits of a very simple driving connection between the spindlec and the splined transmission shaft Y. That is to say, a Worm y issplined to the shaft Y and 1s journaled in the head H so that as thehead moves up or down, the worin will be correspondingly shifted on thesha-ft Y and a Wornrvvheel c is atlixed to the spindle c and its teethare so cut that the meshing vvillrbe perfect although the worm and Worm-Wheel are at an angle to each other.

The other non-splined transmission sha-lit 'E is journaled in. the bedof the machine and has a worm s aliixed thereto for driving the spindleW through the worm-Wheel 'lhe pair of cha-nge gears .of and e?"establish the driving relation between the intermediate power shaft andthe transmission shaft Z; it being observed that this arrangementprovides a balanced drive in which the tour gears W2, .2', 22 and m2transmit the motion to the Work spindle, and likewise four gears c', y",y and w transmit the motion to the cutter. Further details willbedescribed in connection with an explanation of the manipulations of themachine.

To start the machine the power lever B is actuated. A This shifts thecollar 8 and slides a long key. 9 (which is translatably counter-sunk inthe shaft P) and this key aetuates a suitable clutch (not shown) betweenthe prime mover P and the shaft P. The transmission elements previous]scribedA are then maintained in motion y the lll() 'which is frictionapower and the cutter and the work are both revolvin at the relative ratedetermined by the two c lange gars z and m2.

To shift quie ly' the stanchion the U is manually actuated and thisshifts the link U` len hwise andaccomplishes two things, i. e., 1tthrows outthe clutch F and isolates the shaft F `(which transmitsfeeding motion to the spindle head) s0 that all such feed isdiscontinued, and it also throws in the clutch Se to enable motion to betrans-V mitted from the gear S to the gear S7. The feeddiscontinuin,l`clutch F7 is shiftedby'a lever U and the stanchion-actuatinr clutch S8is shifted 'by a -shoe U3 on. the link U2. lVith the parts in theposition described,fthe stanchion may be shifted quick-ly by powereither towards the work or away from the work or not at all; dependingupon the'position of the hand lever a shown 1n detail by Fig. 11. Fastto the pulley P is a gear Q which permanently meshes vwith a gear Q lyconnected through the leather facings 17 and 18 of the clamp disks 19and 20 with the shaft Q2; a nut 2l serving to determine the amount ofthe friction. In this maner, the shaft Q2 is driven simultaneously with,but impositively by, thepulley P so that slippage may occur and breakageprevented -in case the stanchion .be brought against some obstacle. Onthe end of the shaft Q2 is a bevel gear Q3 which permanently meshes withthe right and left -bevel gears Q4 and Q5 which are loosely mounted onthe shaft Q7. A clutch Qa is splined' to the shaft Q7 and when shiftedto the one side or the other will'canse that shaft to rotate either oneway or the other; or not at all if the clutch Qe be in neutral position.The position of the clutch is determined b v a finger `c projectingy.from a lever on the rock-shaft d which, through the bevel gears c andc', is actuated by the rockshaft b which is rocked by the hand-lever a.On the shaft Q7 is alixed'a gear Q8 which drives a gear S0 and (when theclutch SS is connected) the drive is communicated to the gear S7 and thegear S0 is thus rotated.- That gear is in turn spline'd tothe screw Swhich runs through the fixed nut vN and causes the screw to translatebodily;

this translation being communicated to the stanchion by means of anappropriate lug or part S4 journaled to the screw. In this manner, thesta-nchion is quickly traversed by power to the right or to theleft asthe case may be.

To manually shift the stanchion a handwhecl V (providedwith graduationsor micrometer adjustments) is atlixedtoa shaft that carries an anglegear V which 'meshes with an angle gear V2` which is splinefl to thescrew S5 and enables it to be turned by hand. The above described quicktraverse in conjunction with the manual means enlever ables the uservery readily tobringthe stanchion to any desired position with respectto eters. .-1

' To feed the stanchion the shaft Q7 is driven at a slower rate by meanswhich will now be described. This' feedingv of the stanchion is employedwhen it is desired to cut-worm gears as distinguished from spur orhelical gears. The feeding motion is conveyed by va transmissionconsisting of an angle gear 1 mounted on the shaft Zv and meshing withan angle gear 2 aflixed to the' shaft 3. A worm 4e on ythat shaft drivesa worm-Wheel 5 which turns the shaft 6 through appropriate change-gearsdesignated generell by 7 The gear r2 is driven and this gear 1s atliXedto a sleeve 1' which is loosely mounted on the shaft Q but may beconnected thereto by the clutch-teeth r. A shifter pin p may bodilyshift the sleeve 1 to establish or dis-` connect the parts described;this shifter pin being loosely mounted on the shaft o. .A yieldabledetent p acts on the shifter pin so as tourge the parts into clutchingrelation; the purpose being -to provide a quick yet not too positive anaction. Bevel gears 'n and 11, connect the shaft o with a rockshaft-mand a hand-lever c permits the rock-shaft m to be moved manually. On

this rock-shaft m is a smal] arm m which will be correspondinglyimparted to the rock-shaft o which carries the part p7 provided with theaforesaid yielding detent p to throw the sleeve clutch 11 impositivelyinto operative position and provided also with the lug p2 to throw itpositively out.

Thus it will. be seen that vif the hand-lever a be set in neutralposition so that the quick .traverse transmission lis. out of action,and

if the hand-lever 7s be set in position to connect the gear Qs with thefeeding transmission, then will the stanchion be caused to feed (if thehand-lever U is in) and the actionl will be appropriate for the cuttingof the teeth of worm-wheels. Interlocking means, which will be explainedsubsequently, prevent the user from connecting si1nultaneously thefeeding and the quick traverse transmissions with either the stanchionor the cutter supporting head.

To feed the cutter head the parts will be brought into the positions andrelations last described for feedingthe stanchion with the exceptionthat the hand-lever U is thrown out, I that the gear S" is isolated andruns idly. When the clutch S8 is disconnected, the

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This disconnects the clutch S8 so f 'clutch F7 is engaged with theresult that the shaft F6 is .connected to the shaft Q7 and runs at thesame rate which, as has been explained, is determined bythefeedchangegears designated generally by 7. Angle gears F5 and li"transmit the motion to the shaft F3 which is journaled in the stanchionand, at its upper end has a gear F2 which meshes with a gear F which isa unit with a nut that. turns about the non-rotatable feedserew l?. Thatfeed-screw is aflixed to the head H and is caused to move up or down, asthe case may he, by the rotating nut and, in this manner, the cutterjournaled on the 5 head H is caused to feed downwardly'whenever theparts are connected up as described, or to make a quick traverse eitherup or down when the parts are differently connected as will bedescribed.

To shift quickly dovrn the cutter head, the lever a must be moved downinto the lower dotted position shown hv Fig. 11. Before this can bedonc, the block pin g must be pulled against its spring out of the pathof that lever. rThis temporary obstruction is precautionary so that theuser will be obliged deliberately to perform an extra op eration tobring the head dou'n rapidly; otherwise he might inadvertently pressdown the lever o and cause the cutter t9 be brought down rapidly intothe work and broken. From what has been said heretofore, it will he seenthat this depression of the lever a: connects the shaft Q7 with a highspeed transmission and. since that shaft may also he connected with alow speed transmission, it is essential that the one shall be out before the other can come in and conversely. This safeguarding isaccomplished by the .interlock shown hy Fig. 1l in Which the handdcverL' that controls the connection of the sloiv motion transmission (thefeed) has an arm k2 provided with a V-shaped finger which (when the feedis on) enters a central recess in the ledge o2 of the lever e;

lillhen, however, the lever e is not in its heutral position, thefinger. f will, by reason of its double slope, be forced out of therecess and caused to ride on the higher portions of the ledge a2 andthis can only happen when the feed-lever 7c is in the dotted position indicated hy Fig. 1l. ln other words, When clutch QG is in either itsright or its left engaging position, clutch r is disconnected, and whenclutch i" is engaged. clutch Q can h e only in its neutralnon-transiiiitting position. Therefore, by pulling out pin o and bydepressing the lever a. the feed is disconnected and the `quick traverseis aecomplished and the head ll moves down rapidly; providing. ofcourse. that the hand-lever U is in such a position that the clutch S8which moves the stanchion is disconnected and the clutch F? which movesthe cutter head is enf gagged.

Learntec affixed in any desired position lengthwise 0n those shafts. Asshown hy Fig. 8, dogs 25 and 26 are on therock-shaft l) and these dogshave bevel contact surfaces which may engage either one or the other ofthe pins 27 and 28 whenever the box S5 (which is a part of thestanchion) moves suiciently to the right or to the left to engage eitherone or the other of those dogs. The engaeeincnt effects a rocking of theshaft b to lering the hand-lever a to its neutral position and to renderidle the clutch Q0 and thus arrest automatically the travel of thestanchion. Likewise, if the stanchion be feeding, a dop; 29 on therock-shaft fm. will be engaeed by the pin 30 and that shaft will be roc(ed to move the feed lever upwardly into its neutral position whichmeans that the clutch r will. he disengaged and the stanchion will ceaseto feed. The mechanism therefore provides safeguards against any lack ofattention on the part of the user when the stanchion is being traveledeither rapidly or slowly. i 1

To adjust the limits of the quick traverse travel of the cutter head,this invention provides a shift-rod T pivoted to the free end of an arm31 extending to the right as shown by Fig. 11) from the pivot of thehand-lever a, so that, when lever a iS depressed. the shift-rod T willrise, and conversely.' Hence if said rod T be pushed down, the effectwill be the saine on the control mechanism as if the user had pulled upthe hand-lever a.

New, adjustably bolted (by slot 10 and bolts il) to the cutter-head H isa camplate D. This has an inclined face 12 and into the path of travelof that face will be (when the quick down traverse is on) the finger 1Gon the end of the lower arm of a hell-crank lever E which has a fixedpivot at l5. The shift-rod T is pivoted at its upper end i4 to the otherarm of that bell-crank lever. Hence; when the shift-rod is raised toproduce a quick down-traverse) the finger 16 will be in the path of thecamplate l). lf new the cutter-head descends, the inclined face will indue time contact with the linger 16 and depress the shiftrod T: thusraising the hand-lever a.

But this automatic raising of the handlever a (corresponding to adepression of ilo ` down the hand-lever a, he would be the'shift rod Twill ceas'elas 'soon as the,

notch in the surface at2 and the down-feed ofthe cutter-head will besubstituted for the down quick-traverse. The cutter is now about toenter the Work at a feed rate only and cut the gear-teeth. If \now theuser should try, through a mistake, to push re vented by the finger 16which is now ri ing alon the non-sloping face 13. Therefore, the ownquick-traverse is limitedy (by adjusting the initial position of ,thecam plate D) and the user cannot commit the error ofcausing the cutterto enter the work at any rate faster than'that of the normal feed. Y

To adjust the limit of the upward quicktraverse, the collar orov dog T2is set at the appropriate point on the rod T so that the projection(affixed to the vcutter-head) will engage said collar and move thetraverse rod T upwardly and Athereby depress the hand-lever a from itsraised into its neutral position. This will stop the travel of thecutter-head H because the detent shown by Fig. 10 will hold thehand-lever k in the dotted line position shown by Fig. 11 until it isactuated by hand.

To limit the extent of feed there is an adjustablecollar 33 -on the feedshift-rod 34 which controls the-position of the 'hand-*f lever Z: aswill be understood. Also,asa matter of precaution, collars T', 36 and 37are permanently affixedl to the respective rods T and 34 to prevent theuser from making any adjustments beyond the maximumv scope of travelprovided for the cutter head H. l

It may be noted, in regard to the control system, that the automaticthrow-out of the feed when the quick-traverse is thrown in to elevatethe cutter-head makes it easy for the attendant to check carefully theprogress of the cutting operation. Thus, to measure the depth of cut orthe thickness ofl a tooth, the attendant -merely needs to elevate thepower-traverse lever and the cutter-head will forthwith quickly rise.The attendant does not, therefore, have to first operate a feed-lever tothrow out the feed, and then to operate the quick-traverse lever, butmerely the latter alone. n

Without further analysis, the foregoing will so fully reve-al the gistof this invention that others can, by applying current knowledge,readily adapt it for various utilizations by retaining one or more ofthe features that, from the standpoint of the prior art, fairlyconstitute essential characteristics of either the generic or specificaspects of this invention, and, therefore, such adaptations should be,and are intended to be, comprehended within the meaning and range ofequivalency of the following claims.-

Having 'thus revealed this invention, I- claim as new and desiretojsecure the following combinations and elements, or equivalentsthereof, by Letters Patent of the United States:

- 1. A hobber combining a head; auicktraverse mechanism; a manual contronormally available forV causing said mechanism quickly to traverse'saidhead in either of two opposite directions; and an interlocklp'ositionable by said head when adjacent a kpredetermined zone toprevent said control from being so actuated as to vcause said head toenter said zone at a quick traverse rate.

2. A hobber combining a head; means for feeding it in a given direction;a quicktraverse for shiftingit in opposite `directions; a vfeed-lever; atraverse lever; and a member shi-ftable into a position preventing saidquick-traverse from operating -said head in said given direction but notin an opposite direction.

3. A hobber combining a head; means for feeding it in a iven direction;a quicktraverse for shifting it in opposite directions; a feed-lever;atraverse-lever, a member shiftable into a position preventing saidquick-traverse from operating said head in -said given direction but notin an opposite direction; and means for adjustably connecting saidmember and said head whereby ,saidy member will be shifted into saidpreventing position only when said head has been moved a definitedistance in said given direction.

LA hobber combining a head; a quicktraverse. mechanism; a manual controlnormally available for causingsaid mechanism quickly to traverse saidhead in either of two opposite directions; and a member adjustablymounted on said head andadapted when adjacent a predetermined zone toprevent said control from bei-ng so actuated as to cause said head toenter said zone at a quick traverse rate, but not to revent it fromretreating rapidly from said zone.

5. A hobber combining a head; feedmechanism for vfeeding it in but onedirection. a traverse-mechanism for shifting said head rapidly in eitherof two opposite 'directions; a hand-leverfor manually determining .theaction of said traverse-mechanism; manual means normally available forcausing said feed-mechanism to feed said hea-d; and an interlock forlocking said manual means against being manipulated to start and thensaid feed-mechanism while said traversemechanism is operating eitherforwardly or roversely.

6. A hobber combinin a head; means for feeding it in a iven irection; aquicktraverse for shiing it in opposite directions; a feed-lever; atraverse-lever; an interlock for throwing the former out when the latteris in; a member shiftable into a position preventing saidquick-.traverse from operating said liead'in said given direction butnot in an opposite direction; and means for adjustably connectino` saidmember and said head whereby said7 member will be shifted into saidpreventing position only when said head has been moved a definitedistance in said given direction.

7. A hobbercombining a head; a quick- -traverse mechanism; a manualcontrol lnormally available for causing said mechanism quickly totraverse said head in either o f two opposite directions; and a camhaving. Ia bevel and a flat, the flat beine adapted when said head hasentered a predetermined zone i to prevent said control :from being soactuated as to cause said head to advance at a quick traverse rate, andsaid bevel being.

adapted to operate said control if set to produce an advancequick-traverse.

8. A hobber combining a head; means for feeding it in a given direction;a quicktraverse 'for shifting it in opposite directions; a feed-lever; atraverse-lever; and a cam havin a bevel and a at for shifting lioldingthe traverse lever in a position preventing said quicktraverse fromoperating said head in said given direction but not in an oppositedirection.

9. A hobber combining a head; means for feeding it in a given direction;a nick-traverse for shifting it in opposite irections; a feed levershiftable into a neutral or a sin le operative position; a traverselever shitable into a neutral or into either of two operative positions;an interlock for coinpelliiig said feed lever to occupy its neutralposition whenever the traverse lever is in either of said two operativepositions; a yieldable detent for normally holding said feed lever fromreturning to its operative position; and mechanism in part mounted onsaid head and operative (ag at a selected station to shift said traverseever from its one operative position into its neutral position, (Zi)thereafter to prevent a return of said lever but not to prevent it frombeing i shifted into its other operative position.

l0. In a liobbing machine, means for supporting the cutter and the workin a variable relation; quick-traverse mechanism for quickly varyingsaid relation; feed mechanisin for slowly varying said relation; and aninterlock for enabling said quick-traverse mechanism to be operatedreversely durin any relation betweenthe cutter and the avori.

and to be o erated forwardl at any time other than w en the cutter is intooling relation with the work.

1l. In a bobbing-machine, a feed mechanism; a quick-traverse mechanism;and means for limiting the extent ot operation of the latter, saidlatter being c onstructed to permit the operation of the feed mechanismafter the quick traverse mecliai nism has ceased to function and toprevent the latter from being put into other than reverse operationafter the feed mechanism has been put into forward o eration.

l2. A bobbing-machine com ining a quick-- traverse mechanism; controlmeans for causing it to function forwardly, idly or Vreversely; and anauxiliary check device necessitating an abnormal manual operation as acondition precedent to such a setting of said control as will cause thequick-traverse mechanism to function forwardly.

13. In a bobbing i machine, selectively l available mechanismscomprising a forwardly and reversely acting quick-traverse mechanism,and a feed-mechanism operable' in but one direction; and means forautomatically Y rendering the latter ineffective' when the former is putinto operation.

, 14. In a bobbing-machine, a quick-traverse mechanism; a manual controladapted to cause it to operate forwardly; a clie'ck device.necessitating a preliminary manual manipulation before said control canbe thus set;

and a vpositively acting instrumentality for,

restoring said control to an initial positioni as soon as saidquick-traverse mechanism has attained a predetermined station in itsforward operation.

l5. In a bobbing-machine, means for supportingthe cutter and the work ina. variable relation; quick-traverse mechanism for quickly varying saidrelation; feed mechanism for slowly varying said relation; and a controlsystem adapted to be manually and automatically operated, 1st manuallyto 4start the quick-traverse forwardly, 2nd automatically to stop itwhen the cutter is.

about to perform a tooling operation, 3rd manually to start the feedmechanism whenever tlie cutter is to perform a tooling operation, 4thautomatically-to stop the feed mechanism when the cutter has performedits operatori, 5th manually to start the' iso traverse mechanism hasceased to function and to prevent the latter from being put into otherthan reverse operation after the feed mechanism has been put intoforward operation.

18. A hobbing-machine combining, a quick-traverse mechanism; control.means for causing it to function forwardly, idly or reversely; anauxiliary check device neces.- sitating an abnormal manual operation asa condition precedent to such asetting of said control as will cause thequick-traverse mechanism to function forwardly; and manualvmeans adaptedat any time vto cause said'y quick-traverse mechanism to functionreversely. y, v n

19. In a hobbing-machme, aqulcktraverse mechanism; a manual controladapted tocause it to operate forwardly;`a check device necessitating apreliminary manual manipulation before said controlcan be', thus set; apositively acting instrumentality for restoring said control to an idleposition as soon as said quick-traverse mechanism has attained apredetermined station-inl its forward operation; and manual means forcausing said quick-traverse to function reversely at any time within thelimits o f its full scope of operation.

20. In a hobbing machine, the combination of mechanism for synchronouslyrotating and relatively translating the work and the cutter spindles, ofmeans for effecting said translation either at selective-'relativelyslow positive rates or at a non-selective'quicktraverse impositive rateforwardly or reversely. v

21. A bobbing-machine combining a shiftable stanchion; a cutter-headslidable thereon; an intermediate transmission; a rst l f clutch (r) toslowly drive it; a second clutch (Q0) to rapidly drive it; an interlockinhibiting the simultaneous engagement of both of said clutches; a thirdclutch 88) for shifting said stanchion; a fourth c utch (F7) for slidingsaid cutter-head, said four clutches being included in the transmissionsystem between the main-shaft, the shiftable stanchion and thecutter-head; and an interlock preventing simultaneous engagement of saidlast two clutches. a

22. A hobbing machine combining mechanism for relatively translating thework and the cutter spindles; alternatively available means for"effecting said translation either at selective relatively slow positiverates or at a non-selective quick-traverse impositive rate forwardly orreversely; and independent mechanism for synchronously rotating saidspindles. 23. A hobbing-machine combining a shiftable stanchion; acutter-head slidable thereon; an intermediate transmission; a first.

clutch (r) to slowly drive it at selectively available feeding rates; asecond clutch (Q6) to rapidly drive itbut im ositively at a constantrate; any interlock inlliibitin the simultaneousengag'ement of both ofsaid clutches; a. third clutch (SB) deriving motion from saidintermediate transmission shifting said stanchion; a fourth clutch (F7)also deriving motion from it for sliding said cutterhead, saidfourclutches being included in the transmission system between themainshaft,the shiftable stanchion and the cutter- `head; an interlockpreventing simultaneous engagement of said last two clutches; and atransmission system unaffected by any of said clutches for conveyingmotion to rotate relatively the cutterand the work.

. 24. A hobber combinin a head; feedmechanism available for feeding itin but one direction; a traverse-mechanism for shifting said headrapidly in either of two opposite directions; a manual control forstartin termining the direction of its action; and means o erable bysaid manual control for automatilly rendering said feed-mechanismimpotent when said manual control is manipulated to vstart saidtraverse-mechanism either forwardly or reversely.

In witness whereof, I hereunto subscribe my name.

WILLIAM. F. Zmian'aNN.

said traverse mechanism and for de-

